- #1

- 698

- 18

##\vec{e}_{\alpha} \cdot \vec{x}=x^{\alpha}##

and also

## \langle \vec{e}^{* \alpha}, \vec{x} \rangle =x^{\alpha} ##.

If I understand this ##\vec{e}_{\alpha}## is unit vector in direct space, and ##\vec{e}^{* \alpha}## is unit vector in dual space, and the bracket ##\langle, \rangle## is like dual vector on vector on direct space. But why result is ##x^{\alpha}##?